Kingdom Eubacteria • Unicellular (single-cell) • Prokaryotes (no membrane-bound organelles) • Cell Walls contain peptidoglycan, not cellulose • First appeared approximately 3.7 BYA
Nutrition • Autotrophs- manufacture organic compounds • Photoautotrophs- use light energy & CO2 • Chemoautotrophs-use inorganic substances like H2S, NH3, and other nitrogen compounds • Heterotrophs- obtain energy by consuming organic compounds • parasites- get energy from living organisms • saprobes (saprophytes)- get energy from dead, decaying matter; also called decomposers
Heterotroph Ingestion & Digestion • Bacteria cells digest foods by releasing enzymes (which are usually poisonous) outside the cells and into their food. This is called Extra-cellular digestion. • The digested foods are then absorbed by diffusion or active transport.
Oxygen Preferences • obligate aerobes must have oxygen • obligate anaerobes cannot live in oxygen • facultative anaerobes can grow with or without oxygen
Characteristics used for Classification: • RNA sequences and structure • type of nutrition • ability to produce endospores- resistant structures with cytoplasm and DNA • method of movement • shape, and the way the cells are grouped • composition of cell wall and it’s ability to absorb stain
General Characteristics • are found almost everywhere • are often pathogenic (they make us sick!) • are divided into groups according to: • their shape • grouping • cell wall • ability to absorb stains
Shapes • Coccus = spherical (coccus came from the Greek word for berries!) • Bacillus = rod-shaped • Spirilla = spiral-shaped
Grouping • Diplo- Pairs • Streptos- Chains • Staphylo- Clusters http://genome.microbio.uab.edu/strep/info/strep5.gif http://library.thinkquest.org/03oct/00520/gallery/thumbnails/thumb_diplococcus.jpg
A Group of Two is referred to as: Diplo…….. This is diplococccus
A Cluster of cells is referred to as: Staphylo…. This is Staphylococcus
Gram Stain • A staining method to differentiate bacteria • Gram-negative refers to the inability to retain the deep violet dye • Gram-positive refers to the ability to retain the deep violet dye
Gram Negative cells Gram Positive Cells
Bacterial Diseases • Anthrax • Botulism • Lyme Disease • Salmonella • Tetanus • Tooth decay • Tuberculosis
Bacteria Photos Clostridium perfringes Anthrax
Bacteria Photos E. coli Clostridium tetani
Bacteria Photos Neisseria gonorrhoeae Staphylococcus aureus
Bacteria Photos Strep
Cyanobacteria • are photosynthetic autotrophs that produce carbohydrates and oxygen • tend to cling together in chains or colonies • contain enzymes that allow them to “fix” atmospheric nitrogen
Filamentous: Chain of cells http://www.spea.indiana.edu/joneswi/e455/Anabaena.jpg
Anabaena _ http://www.bio.mtu.edu/~jkoyadom/algae_webpage/ALGAL_IMAGES/cyanobacteria/Anabaena_jason_dbtow17 2016.jpg
Some filamentous cyanobacteria have Heterocysts, which are Nitrogen-fixing structures http://www.people.vcu.edu/~elhaij/IntroBioinf/Scenarios/heterocyst2.JPG
Nitrogen-fixation • some soil bacteria live in the ground and take in Nitrogen from the surroundings. • the Nitrogen is combined with oxygen to form nitrites and nitrates. Plants use the nitrates and nitrites to make proteins.
Denitrification • some soil bacteria break down the nitrogen compounds and release the nitrogen back into the environment. • plants could not live without Nitrogen-fixing and Denitrifying bacteria.
Asexual Reproduction • Binary Fission – cells grow in size the split in two…. Genetically identical
Sexual Reproduction (exchanging DNA)Conjugation • two bacteria join together and exchange portions of DNA
Transformation DNA is taken in by a bacterium, and then used.
Transduction DNA is transferred to a bacterium by a virus.
Endospores • When environmental factors become harsh bacteria will either die or form endospores. • If bacteria have time, if the environmental changes are slow enough, they usually form endospores.
Examples of Symbiotic Relationships • Mutualism – E. coli in the intestines of mammals aid in digestion. • Parasitism – some bacteria are parasites. They live in a host and eventually overpopulate. As they do they use the host’s food and water, and eventually they starve the tissues.
Beneficial Uses/Effects • chemical recyclers (Nitrogen Cycle) • the production of HGH, Insulin, Etc., through Genetic Engineering • oil spill cleanup • synthesis of Vitamins in your intestines